I am just looking at big shapes and lights and darks. I've added French ultramarine for the shadows and am using turpentine to pull off color for the lights.
I am using some charcoal to do some drawing now. I still do alot of the drawing with my brush... I also am working on the outline now. The horse will be back lit. The face is in shadow so I am not rushing to define that very much at this point.